Triangle computing and drafting instrument.



T. H. M. cRAMPoN. TRIANGLEl COMPUTING AND DRAFTING' INSTRUMENT.

APPLICATION FLED JULY 5, l9l7' I 1,262,023@ Patented Apr. 9,1918.

79 A JNVENTOR.

ATTORNEY.' y

TAES PTENT FFQF.

THEODORE I-I. M. CRAMPTON, OF SANTA MONICA, CALIFORNIA.

TRIANGLE COMPUTING AND DRAFTING- INSTRUMENT.

Specification of Letters Patent. Patented Apr'. 9, 1918.

Application filed July 5, 1917. Serial No. 178,815.

ing board for solving all plane trgono;-

metrical problems without the use of natural functions, logarithms, or other aids.

One of the principal objects of this invention is to provide an instrument which is simple and accurate, and which can be rapidly manipulated by engineers, navigators and military men for determining any or all of the sides and angles of a triangle at one setting; for determining the course of travel of a ship or other moving object; for ascertaining the height of an aeroplane, or the distance of an object from points of observation; and by means of which, when known observations are given, the instrument can be quickly adjusted for making the. necessary calculations and determining the unknown elements,the results being indicated directly on the instrument.

Another object of the invention is to proide an instrument of the character referred to having protractors and scale arms so constructed and' arranged that the parts thereof can be quickly and accurately adjusted relative to each other for the purpose of reproducing any triangle, together with means for accurately indicating all the sides and angles of the reproduced triangle, and at the same time providing such an instru- 'ment as can be used for laying out upon a drawing board the angles and distances indicated.

Another object of the invention 1s to provide in an instrument of the character referred to means whereby parallel lines may be produced without the necessity of using a protractor.

In order to describe my invention, I have illustrated one practical embodiment thereof on the accompanying sheet of drawings, which I will now describe.

Figure 1 is a plan View of the instrument,

length thereof.

certain parts being broken away and shown in section;

Fig. 2 is a cross sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a cross sectional view taken on line 3 3 of Fig. 1;

Fig. -l is a cross sectional view taken on the line 4 4, Fig. 1.

The device forming the subject matter of `this invention is designed to afford meansV by which mathematical problems particularly relating to trigonometry can be solved without the use of tables, or other aids. Referring lnow more particularly to the drawings, the invention as here embodied, comprises a frame 10, preferably in the form of a protractor 11, one side of which is designated as a base member' 12, said frame being also provided with a cross member 13. rEhe upper edge 14: of the base member 12 is provided with graduations,v

and is used as the base line of the protractor. The base member 12 is provided with a guideway, as 16, extending Ythe Slidably and detachably mounted on the base member 12 is a secondary protractor 17, provided with a bead 18, formed thereon near. the lower edge thereof, and which interl'its with the recess 19, formed in the base member 12, as clearly indicated in Fig. 2 of the drawing. rl`he secondary protractor is mounted to be moved along the base member 12, and within the arc thereof, and to this end is smaller.

The frame 10 is also provided with a pair of parallel guideways 20 and 21, formed, respectively, in the base member 12, above the guideway 16, and in the cross member 13. Slidably mounted in these two guideways are the ends of a bar 22, which is adapted to slide laterally from side to side. The upper surface of the bar 22 is provided with graduations, as 28, similar to those on the base member 12.

Detachably secured to the lower left hand corner of the protractor 11, is a two part bearing member 2a, which is held in said frame by means of screws 25. Mounted in this member is a hub 26, which is preferably formed with an opening 27 therein. Mounted in this opening is a transparent cross .line member 28 'so positioned that the point l and 32, and the base line 14, are used to Yatene setting of the said parts.

Vment upon the protractor 11.

adapted to swing over 'the protractor 1l. lllie .voi-lring edge of said scale arm has a scale, 81, inscribed thereon, which is also in the same proportions as the scales 15 and 23. lt Will be observed that .the location of the edges of the scale bars or arms are alladjaeent to each other, .vhereby a triangle which may be drawn or measured by said arms vvill have the length of its sides read directly from said scales.

Y rlhe secondary proti'actor is also provided With a scale bar 32, Whichinay be used for the draitingor measuring of angles, and the working edge 83, thereof, 'which has a scale 34 inscribed thereon, intersects thecenter 35 of the protrae-toi' 17. rfhis bar, as here shown, isconstructed with a slot 36 formed therein `toi' its length. Slidably mounted in said slot is a vernier piece 37, which has an opening 38 formed therethrough, in register With the slot 39, formed in the secondary protractor, whereby a bolt -i-O is closely fitted therein and provided With a thumb nut 41, for securing the scalebar 32 in adjusted positions, as desired.

The bar 22 is used ior drawing or measuring vertical lines yand also the altitudes ci triangles, while the other -bars or arms, as 30 measure and indicate tliesides or triangles I it all points Where accurate and careful readings are necessary, l prefer to provide verniei's, as 4t2, e3, ell and V45.

The 'frame 10 isalso provided with a slot, 1li-6, adapted to permit the secondary protraetor to slide the entire Width oi the frame,

Vwhereby its center can be moved along the base line la iior its length. rlhe said protractor may be detached trom the trame, 'it

desired. il. lock nut d? is provided upon theV carrying member 24, tor holding the scale arm 30st any angle or position or" adjust-- Y l lt Will also be observed that the members 30 and 32 are mounted in the Ysame plane, above the trame 12, and the bar`22. riliev ernier is adapted to move in a slot l9,'in the protractor i7,

and is held in any position desired bya ythumb screw 50. inscribed upon the inner edge of the protractor 11 is a grade scale 9,

which permits anv operator oi" the instru-A ment to read directly .fromA said scale the "grade of any elevation laid out upon the 55` langle tormed'betiveen the base line 14, and the scale arm 30. This scale is so proportioned that the-percentage et grade indi.-V

cated thereby can be read directly therefrom. n ,The many uses to which this instrument changes can be made in the details' of construction and arrangement as here shown for purposes ci illustration, without departing from the spirit or" the invention, and l do not, therefore, limit the invention to this showing, except as: l may be limited by the hereto appended claims.

I claim:

1. An instrument oit the character referred to comprising` in combination, a protractor having` base member, and a secondary protraetorslidably mounted on said base member, Withintlie are of said first prot-rector, the centers oit said proti'actois being in alineinent with the Working edgeot the base member.

in instrument ot tl'e character ie ed to comprising, in combination a pro'A having a base member, the upper i said base member being the base line l pi'otiactoi' and intersecting the ccnid preti-actor, a secondary protracly mounted on said base member lNithin die are oi? said iirstpi'otractor, and

iaving` it center on said base line, and'scale arms' inovably'mounted on said protractors.V

haring a scale thereon, a protractor ori-said'` base member, the' center thereotjcoinciding with said upper edge oi said base member, a second proti'actor slidably mounted on said member, Within the arc. of saidffirst.

protractor, rotatable arms carried by said preti-actors, the adjacent edges oic Vsaid arms having scales thereon, and, anarm movable on 'and perpendicularto said base member and having` a scale thereon.

5. An instrument ot the .character vreferred to comprising a traine having a protractor scale formed thereonl andalso having a base,a protractor slidablymounted on said trame, swinging scale armsi'mounted on said protractor and trame, the Working'edges ot said scale arms7 Whenextended, intersectingthe` centers ot said pr'otractor Vand protractor scale, and ascale bar 'perpendicular tothe. base oit said trame and movably mounted on said traine. Y 1

6. In an instrument of the character referred to, tivo Protractors, onebeing; ,slid- Vably mounted Within the other, swinging-scale bars operating inconjunction with saidprotractors, Va laterally movable scale ba ri adapt-Y ed to be moved Within the held of said combination, ai rbase,

swinging bars, verniers for said scale bars, and means or hoiding said hars in adjusted positions with respect to Said protractors.

7. An instrument comprising a frame having two Sides at right angles to each other and having a protractor scale thereon, a eeaie arm pivotaiiy connected to the coi ner of said frame to swing over said protractor scale and having cross heirs to indicate the center oi: its pivot and of said protractor Scale, a protractor movahijv mounted on one of sides, a Scale arm shdabiy mounted on said protractor at the center thereof, and a scale bar siidabiy mounted on said Side and at right angles thereto.

8. An instrument comprising a 'frame having a base and having a protractor scale thereon, a scale arm pivotaiiy connected to Said base to Swing over said protractor Scale, a second protractor movabiy mounted on said base Within the are of said first protraetor scale, a scale arm siidabiy mounted on said second protraetor at the center thereof. and a scale oar slidabiy mounted on Said base and at right angles thereto.

ogiea of 5h15 patent may be obtained for ve cents each.,

9. An instrument comprising a frameV having a base and having a protractor Scale thereon, a Scale arm pivotaily connected to said base to swing over said protractor scale and having cross hairs to indicate the center of its pivot and or" said protractor scale, a protractor movabiy mounted on said base, a seaie arm eiidably mounted on said protractor at the center thereof, and a scale bar siidably mounted on sad base and at right angles thereto.

10. in an instrument of the character referred to, a protraetor having a base and a graduated are, a scale arm pivotaliy mounted thereon to swing over Said graduated are, a second protractor siidabiy mounted and adapted to he moved within the are oi? said first protraetor, a Scale arm swingingiy and siidaoiy mounted on said second pro- `rac-tor, and a Scale oa-r movabiy mounted at angles to the hase said iirst protractor., euhstantiaiiv as described.

ntestimonjyY whereof, have hereunto eet my hand.

THEODORE H. M. CRAMPTON.

by addressing the Qommssioner o Patente,

Washington. Y). C. 

